A study of hypertension in children has been carried out from the point of view of etiology and to define endocrine causes of juvenile hypertension. We have devised a new five day ACTH test which categorizes hypertensive children into two groups: one which responds with rise in blood pressure and one which does not. From this test we will develop a hormone profile of each group. Secondly, we have demonstrated in a new kindred with dexamethasone-suppressible hyperaldosteronism that the hypertension is volume dependent and ACTH stimulable. Blood pressure was only reversible in the children and not the mother though aldosterone was suppressible in all. This indicates the necessity of studying the pathogenesis of hypertension in the young. We have also demonstrated that aldosterone is detectable in saliva and correlates well with plasma hormone levels. A nomogram relating urinary aldosterone to urinary sodium for children has been developed.